1. Field of the Invention
The present invention concerns a method for automatically determining the sagittal plane for the examination regions of an object by means of a magnetic resonance apparatus.
2. Description of the Prior Art
In the acquisition of images of an examination object by means of magnetic resonance, knowledge of the location of certain preferred planes regarding the examination object is important, such as to have knowledge about the relation of the examination object to the coordinate system of the magnetic resonance device, and to exactly define the plane of the slice images that will need to be acquired. Furthermore, knowledge of such distinct planes is important to acquire comparable slice images within the context of repeated examinations.
One such plane is the sagittal plane. Every body plane parallel to the middle plane of the body or the arrow seam of the cranium is encompassed by the term sagittal plane. The determination of the position of the sagittal plane or the sagittal position conventionally ensues manually. This knowledge is used to position the examination object as precisely as possible. For instance a patient whose spinal column is to be examined, in a magnetic resonance device should be positioned by the technician as straight and plane as possible. Subsequently multiple reference exposures are acquired (at times with differing contrasts), for instance with T1, T2, or T2* weighting. The number of exposures (approximately 3-5) are made available to a physician, who used these exposures together with specialized knowledge to determine the position of the sagittal plane or the middle sagittal position by visual assessment. With a crooked spinal column the doctor may attempt tot find either a compromise position, or a compromise position corresponding to guidelines set by the device manufacturer. This procedure is complicated and prone to error, because errors in positioning a patient can be made, leading to assessment problems in subsequent exposures. Moreover, difficulties result sometimes in the image assessment, especially if the exposures are either of poor quality or non-existent or contain insufficiently relevant information for determination of the sagittal position.